Heating issue with heatline capriz plus 24a

[Azz]

customer complaining regarding heating running on low heat around 40.c at most, showing on front panel.
Have push up tempreture to maximum of 65c but boiler just dosnt seem to go beyond 40.c.
Hot water works fine.
Its a small flat with 3 radiators 1 large and 2 medium size, have carried out system flush as water was very dirty but has not made much difference.
By removing actuator motor and turning hot water tap on, the heat will go on heating side perfectly reaching tempreture of 80.c and all rads are piping hot, which takes out any doubts about blockage.
Have also replace flow and return ntc's with no effect
The other trouble is there is no technical help with heatline as they seized to exist.

Any help would be much appreciated.

 

[Harvest Fields]

I would recommend getting a new boiler to be honest.

 

[king of pipes]

If no blockages then it a diverter problem these boilers are cheap and nasty but very expensive on parts obviously the heating should not come on when hot tap is operated. As above I would consider a upgrade. Kop

 

[gassed up]

I would check to see if the potentiometer stalk has snapped inside the pcb. May not be turning up the temp.

 

[Azz]

Thanks for the response. Heating does not come on when hot water is on or get heat on the flow beneath boiler. As previously stated that when the actuator motor ir removed and hot water tap on is when central heating gets fully hot, as actuator motor pushes diverter pin for hot water and opposite for heating.
Have also replace pcb recently as heating was not coming on at all but after pcb chage it comes on but upto 40.c

This is a push button for tempreature adjustment which corresponds with digital screen so cant be a potentiometer.

Customer spent a lot of money on this boiler and feels gutted to require a change as im sure its around 5 years old.

Thanks

 

[Harvest Fields]

Time to get an engineer in me thinks.